WASHINGTON — Suddenly, Bruins-Capitals turned into Flyers-Penguins, replete with scraps and all sorts of scrums — not to mention quite a bit of offence thrown in.

From the high stick that knocked off Boston captain Zdeno Chara’s helmet, to the cross-check to Rich Peverley’s face at game’s end that earned a match penalty for Washington’s Nicklas Backstrom, and all sorts of mayhem in between, Game 3 “was kind of like a rugby game,” Capitals coach Dale Hunter said.

“The only thing that’s disappointing for me personally is that this is the third time in three games our player has been cross-checked in the face. … You hope that those things don’t get out of hand,” Bruins coach Claude Julien said. “Somebody else, not us, has to deal with that.”

Thanks to Chara, the Bruins came out on top.

Chara scored the tiebreaking goal during 4-on-4 play with less than 2 minutes left, and the reigning Stanley Cup champion Bruins finally solved playoff rookie goalie Braden Holtby, beating the Capitals 4-3 Monday night to take a 2-1 lead in the first-round Eastern Conference series.

“It’s getting more emotional,” Chara said. “Players are more involved. It’s starting to be more and more physical.”

The 6-foot-9 owner of a 100-plus mph slap shot was involved in pretty much every key play: He was in the penalty box when Alexander Semin scored the game’s first goal for Washington; he had two assists; and his final shot from the right circle appeared to get deflected by Capitals defenceman Roman Hamrlik — “Lucky goal,” Hunter said — on its way past Holtby.

“It was nice to see him get that. He got clipped there in the head; a little frustrated from the non-call. He had a penalty early in the game for I thought just holding his own,” Julien said. “So he’s been good at not getting frustrated at those things. Because he stays with it, he ends up getting rewarded with a big goal.”

Game 4 is Thursday in Washington, before the best-of-seven series moves back to Boston for Game 5 on Saturday.

“Hopefully, it can give us some real momentum moving forward — and we can win a couple games by two goals,” said Tim Thomas, last season’s playoff MVP, who made 29 saves and ignored the taunting from fans who held up photos of President Barack Obama, reminding him that he turned down a trip to the White House in January with his teammates.

Peverley, Brian Rolston and Daniel Paille scored for the Bruins.

Alex Ovechkin and Brooks Laich got Washington’s other goals. Laich scored on a breakaway with 6 minutes left to make it 3-3, but Chara came through with 1:53 remaining for second-seeded Boston.

Holtby, who blocked 72 of 74 shots through the first two games, was good but not great Monday, making 25 saves.

Game 1 went to overtime before Boston won 1-0, and Game 2 wasn’t decided until the second extra period, when Washington claimed a 2-1 victory. Two games and a whopping total of four goals.

There were four goals in 1 1/2 periods Monday — and a lot more hitting and fighting and penalties. After one prolonged skirmish involving a handful of players, Capitals defenceman Karl Alzner made a fist and rotated it near his eye, as if to say to Boston’s Milan Lucic, “Why are you being such a crybaby?”

Afterward, Lucic said that was a rich gesture coming from “a guy who I think has two roughing penalties in three years.”

“We’re a team that stands up for ourselves and stands up for our teammates,” Lucic said. “We’re a team with a lot of pride, so that might be a big reason why we get ourselves going.”

It actually might have been Ovechkin who set the tone right away, flattening defenceman Dennis Seidenberg with a big, roar-inducing hit less than 30 seconds in. About 10 minutes later, Ovechkin rattled Rolston, one of the five hits the Russian accumulated in the first period.

“There was more stuff — extracurricular stuff — after the whistles,” Laich said. “We kind of don’t want to get caught up in that.”

The opening period ended with a bit of a scrum several feet to Thomas’ left. Nothing rising to the level of the rowdy series between Philadelphia and Pittsburgh, but there was enough improper contact that two players began the second period off the ice: Backstrom for cross-checking, and Lucic for roughing.

During the ensuing 4-on-4, the teams produced two goals in 13 seconds, with Ovechkin putting Washington ahead 2-1. The lead didn’t last long, though. Paille — who had nine goals all season, and none since Feb. 11 — tied it by batting down a rebound with his stick, then nimbly getting around Holtby. Rolston put Boston ahead 62 seconds into the third period, before Laich temporarily evened the score.

Chara decided the outcome of Game 3, and both teams braced for more of what several players called “chippier” play.

“You could see some of the retaliatory penalties and a few embellishments out there,” Washington forward Troy Brouwer said. “That’s how it goes, and that’s what happens when you see a team three times in six nights, and it’s only going to be more in the next few days.”

NOTES: Hunter said he expects Backstrom’s match penalty to be reviewed and rescinded. … Ovechkin’s goal allowed him to break a tie with Hunter and move into second in Capitals history with 26 in the playoffs. Only Peter Bondra, with 30, scored more post-season goals for Washington.